We will continue an analysis of tubulin which has been blocked from polymerization by diamide, NEM and oxidized glutathione. The prime aim is to see whether specific sulfhydryls are involved and whether they include a common set for all agents. This work will involve labelling with radioactive agent and peptide mapping. With diamide we will examine peptide under both reducing and oxidizing conditions and will explore for peptides which show alterations in position. We will explore the site of interaction of NEM and GSSG with an acto-myosin gel obtained from sea urchin eggs which can be induced to contract with these agents. We have characterized the components of the gel and should be able to identify the components alkylated by the sulfhydryl agents. Their separation should allow more incisive understanding of their participation in the contraction phase. In addition, we will investigate the participation of purified thioltransferase on their reaction. We will further explore the site(s) of interaction of NEM with the egg surface, an interaction which leads to exocytosis and vitelling membrane elevation. We will use observations on the limited time necessary for NEM to interact with the surface in order to cause elevation, the minimum concentrations necessary and the fact that iodoacetic acid can block the NEM effect without causing elevation itself. Other projects include studies on the reversible interaction of glucose-6-phosphate dehydrogenase with the egg surface, effects of BCNU and its breakdown products on tubulin and isolation of G-6-PD mutants of CHO cells for studies on the effects of diamide and hydroperoxide on the shape of the cells.